Method of preparing beta (o-methyl phenoxy) beta&#39; thiocyan ethyl ether



Patented Oct. 28, 1941 METHOD OF PREPAR/ING {NO-METHYL PHE- NOXY)B'THIOCYAN ETHYL ETHER I Oscar F. Hedenburg, Pittsburgh,,Pa., assignorto Rex Research Corporation, Toledo, Ohio, a corporation of Delaware NoDrawing. Application June 27, 1938,

Serial No. 216,069

2 Claims.

This invention consists in a method of preparing a certain compositionof matter which I have discovered to possess insecticidal propertiessuperior to those of similar compounds heretofore produced.

My improved compound may be characterized as an aromatic alkylthiocyanate, in which the thiocyan group is attached to the alkyl group.Similar compounds previously proposed include aromatic isothiocyanatesin which the isothiocyanate group is attached to the aromatic group; andaliphatic thiocyanates. The compound of my invention consists of anaromatic aliphatic thiocyanate in which, with. respect to the aliphaticchain, the thiocyan group and an aromatic group occupy interchangeablythe 3 and s positions. Typically the compound of my invention is ,8(o-methyl phenoxy) i3 thiocyan ethyl ether, responsive to the formulaThe phenolic group of the foregoing formula is, specifically, cresyiic;any other phenolic group may be present in substitution for thecresylic. This phenolic group of the formula given is of the ortho type;it may, alternatively, be of meta or of para type. The aliphatic groupof the formula given above is, specifically, that of the methylcompounds; any other aliphatic group may be present in substitution forthe methyl group. And there may be more than one aliphatic groupattached to the aromatic group. Other groups may replace hydrogen in thearomatic group, such as chlorine.

The compound of my invention may typically be prepared as follows:

810 grams of ortho cresol, CH3CsH4OH, 1287 grams of flp'dichlorethylether, C4HaOC12, and 50 grams of water are heated to about 106 0., with.

agitation. To this 300 grams of sodium hydroxide (100%) in 50% aqueoussolution are slowly added in ten portions,

In an actual performance, the total time of heating and agitation was alittle more than fourteen hours. The period of the sodium hydroxideaddition was five hours and thirty-four minutes. Each portion of thesolution was added in the course of an interval of average duration ofthirty-three minutes. When the full quantity (300 grams) of sodiumhydroxide solution had thus been added, an excess quantity of tenpercent (30 grams) of the same sodium hydroxide solution was added; andthereafter the heating was continued for three hours.

The essential reaction is according to the equation 0 under distillationyielded film-methyl phenoxy) fichlorethyl ether, 97.5% pure, 1151.5grams (=1122.7 grams C. P.)

. Grams Unused dichlorethyl ether 389.5 Intermediate boiling substance25 Dark residue 164.5

The 1122.7 grams of pure o-cresoxy chlorethyl ether-5(o-methyl phenoxy)fi'chlorethyl etherwas a yield, on the basis of the ortho cresol used,but a 77.4% yield, on the basis of the ortho cresol actually enteringinto reaction. Eighty grams of unreacted ortho cresol were recoveredfrom the aqueous solution that was separated from the 1745 grams ofcrude product, first mentioned above. This recovered material would, incommercial operation, be available for repeated use. Otherwise, the lossof material due to unintended reaction is small.

The o-cresoxy chlorethyl ether obtained in the manner indicated is thenreacted with sodium thiocyanate, according to the following equa- +NaSCNIn actual performance 440 grams (97.5%

72 hours, at a temperature ranging near 130 03. Benzol then was addedand the flask was shaken. a

The contents of the flask were filtered and wash-: ed with benzol. Thebenzol then was distilled 01f, and 487 grams of a brown product wereobtained. v

This product was [Ho-methyl phenoxy) fi'thio cyan ethyl ether of about95% purity.

The use of benzol is not essential. It suffices to add water (todissolve the soft formed) and to be separated by decantation of thesuper- 7 natant layer of the desired product. The forma-' tion of anemulsion may occur and then maybe broken 'by percolation through salt(NaCl). Herein is found the subject matter of a companion applicationfor Letters Patent.

In the performance last described the diethyl amine serves as acatalyst. Other substances that may serve alternatively as catalysts inthis association are morpholine and. other secondary amines.

This substance, /3(o-ethyl phenoxy) fi'thiocyan ethyl ether, I havefound to be superior as an insecticide to the substances of like generalchar acter that have been specified above. It is less objectionable inodor than any of them, and while less toxic to animals (particularlywhen applied to the skin) it is more toxic to insects. When used as aspray it will bring down flies, for example, in equal numbers, and willbe found to be more effective in the killing of the flies brought down.

\ As I have already explained, in place of ortho A meta cresol,

or para cresol,

H o C r specifically, any phenol may be employed.

Also, in place of dichlorethyl ether the dichloride of another aliphaticether may be employed as, for example, dichlormethyl ether,

a flphenoxy flthiocyan ethyl ether in which a,

hydrogen of the phenyl group is substituted by the methyl group whichconsists in reacting l3- phenoxy fi'chlorethyl ether in which a hydrogenof the phenyl group is substituted by the methyl group with athiocyanate in the presence of a secondary amine.

OSCAR F. HEZDENBURG.

